Treesearch

One of the greatest deterrents to establishing a new nut orchard is the long period of time it takes from tree planting to first commercial nut harvest. At the Pecan Experiment Field, a pecan or walnut must grow ten seasons or more and maybe a little less for Chinese chestnuts before the trees produces enough nuts to warrant mechanical harvesting.

To classify trees along a spectrum of isohydric to anisohydric behavior is a promising new framework for identifying tree species' sensitivities to drought stress, directly related to the vulnerability of carbon uptake of terrestrial ecosystems with increased hydroclimate variability. Trees with isohydric strategies regulate stomatal conductance to maintain stationary leaf water potential, while trees with anisohydric strategies allow leaf water potential to fall, which in the absence of significant hydraulic cavitation will facilitate greater rates of carbon uptake. Despite the recognition...

Efforts are underway in the United States to improve the conformance of commercially-treated wood with the applicable retention standards. As part of an effort to devise a practical method for on-site assessment of within-charge retention variation, we investigated whether small-volume x-ray fluorescence (XRF) sample cups could be used with treated wood. A range of cup sizes, preservative types, retention levels and other variables were considered. In general, small volume cups appear to be suitable for use with common industrial XRF machinery. This finding is being applied to a proposed...

Drought has the ability to affect the persistence of small animal populations, especially those tied to aquatic habitats. We studied the response of western pond turtles Actinemys marmorata to California's worst drought on record. From 2009 through 2015 we used telemetry to track movements and assess survival of 19 western pond turtles in a stock pond at the San Joaquin Experimental Range in the western foothills of the Sierra Nevada, in Madera County, California. In 2013 the pond dried in late summer and winter rains were insufficient for pond formation. The pond remained dry through the...

The U.S. Culture Collection Network held a meeting to share information about how culture collections are responding to the requirements of the recently enacted Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization to the Convention on Biological Diversity (CBD). The meeting included representatives of many culture collections and other biological collections, the U.S. Department of State, U.S. Department of Agriculture, Secretariat of the CBD, interested scientific societies, and collection groups, including Scientific...

This study was aimed to identify the best approach for incorporating cellulose nanocrystals (CNCs) into a poly(lactic acid) (PLA) matrix by examining two different CNC addition approaches. The first approach consisted of melt blending PLA and CNCs in a three-piece internal mixer whereas the second method involved the direct dry mixing of PLA and CNCs. The prepared compounded materials were then blown into films and compared in terms of fiber dispersion, optical, thermal and barrier properties. The experimental results indicated that the extent of fiber dispersion was not influenced by the...

Structural complexity is widely recognized as an inherent characteristic of unmanaged forests critical to their function and resilience, but often reduced in their managed counterparts. Variable retention harvesting (VRH) has been proposed as a way to restore or enhance structural complexity in managed forests, and thereby sustain attendant biodiversity and ecosystem function. Here we examined the decade-long response of diurnal breeding birds to a VRH experiment that, for the first time, incorporated both overstory and shrub layer treatments in red pine (Pinus resinosa) dominated forests...

This publication provides an overview of forest resources in New Jersey following an inventory by the U.S. Forest Service, Forest Inventory and Analysis program (FIA), Northern Research Station (NRS). Estimates are derived from field data collected using an annualized sample design and are updated yearly. Beginning in 2014, NRS-FIA switched to a 7-year cycle length. For the 2016 inventory, estimates of current variables such as area, volume, and biomass are based on 1,091 plots measured in 2011-2016. Change variables such as net growth, removals, and mortality are based on 733 plots...

Utilizing lignin-containing cellulose nanocrystals (HLCNCs) as reinforcing agents to poly(lactic acid) (PLA) for nanocomposites was studied for the first time. The PLA/HLCNCs nanocomposites were prepared by extrusion and injecting molding. The freeze-dried HLCNCs showed micron scale agglomerates. As indicated by the water contact angle measurements, the HLCNCs were more hydrophobic than dealkaline lignin and traditional, lignin-free CNCs derived from high cellulose content wood pulp. Thermogravimetric analysis (TGA) showed that the HLCNCs started to degrade at about 300°C. The thermal...

Wood decay elements include snags, down wood, root wads, tree stumps, litter, duff, broomed or diseased branches, and partially dead trees, all of which contribute to ecological processes and biodiversity of the forest ecosystem. Down wood can serve as reservoirs for moisture and mycorrhizal fungi beneficial to the health and growth of commercial tree species. Decaying wood, leaf litter, small twigs, and roots contribute nutrients and structure to humus and soil organic matter, and host microbes that play beneficial roles in nitrogen cycles and other processes. Snags and down wood provide...